A negative test charge is moving near a long straight wire carrying a current. The force acting on the test charge is parallel to the direction of the current. The motion of the charge is:

Question

A negative test charge is moving near a long straight wire carrying a current. The force acting on the test charge is parallel to the direction of the current. The motion of the charge is: (A) Away from the wire (B) Towards the wire (C) Parallel to the wire along the current (D) Parallel to the wire opposite to the current

Tardigrade Admin · Accepted Answer

Force on a moving charge, overset arrow F=q( overset arrow v × overset arrow B) Here, ∵ q=-ve ⇒ overset arrow F=-q( overset arrow v × overset arrow B) ∴ textmotion of-q text is towards the wire. <img class="img-fluid question-image" alt="Solution" src="https://cdn.tardigrade.in/q/nta/p-y5usylrjwvx3qkd2.jpg" />

Q. A negative test charge is moving near a long straight wire carrying a current. The force acting on the test charge is parallel to the direction of the current. The motion of the charge is:

Away from the wire

Towards the wire

Parallel to the wire along the current

Parallel to the wire opposite to the current

Force on a moving charge, $F \to = q (v \to \times B \to)$
Here, $∵ q = - v e$
$\Rightarrow F \to = - q (v \to \times B \to)$
$∴ motion of - q is towards the wire.$

Q. A negative test charge is moving near a long straight wire carrying a current. The force acting on the test charge is parallel to the direction of the current. The motion of the charge is:

Away from the wire

Towards the wire

Parallel to the wire along the current

Parallel to the wire opposite to the current

Force on a moving charge, F→=q(v→×B→) Here, ∵q=−ve ⇒F→=−q(v→×B→) ∴motion of−q is towards the wire.

Force on a moving charge, $F \to = q (v \to \times B \to)$
Here, $∵ q = - v e$
$\Rightarrow F \to = - q (v \to \times B \to)$
$∴ motion of - q is towards the wire.$